Switch lock with toggle-lever driving mechanism for the switch rod



March 24, 1931. E- BESAG =798,058

SWITCH LOCK WITH ToGGLE LEVER DRIVING MECHANISM FOR THE SWITCH ROD Filed Feb. 24, 1928 fm/enfer:

Patented Mar. 24, 1931 UNITED STATES ERNST BESAG, OF BADEN-BADEN, GERMANY SWITCH LOCK WITH TOGGLE-LEVER DRIVING MECHANISM 4FOR. THE SWITG ROD Application led February 24, 1928, Serial No. 256,656, and in Germany February 25, 1927.

This invention refers to a switch-lock or an actuating and locking device for switches in which small releasing forces are sufficient for tripping and which is distinguished by its small size, flat form, and simplicity.

The device contains two toggles from which one toggle serves to connect a driving member with the switch-rod being under the influence of a force tending to open the switch and which transmits a component of this force to a second toggle serving for locking the mechanism. An extremely small irnpulse, that is, a quite slight shifting force of an overload-relay forjinstance a thermie relay, is sulcient to cause the toggle to collapse so that the releasing takes place instantaneousl Ail embodiment of the invention is illustrated, by way of example, in the accompanying drawings, in which:

Figs. 1 to 3 show the switch-lock each in side-elevation and in a different position. Fig. 4 is a front-elevation of Fig. 1. Fig. 5 is an elevation, seen in the direction of the arrow-line P in Fig. 1.

Fig. 6 shows in vertical section the bearing point for the switch handle.

The lock plate 1, having an angular abutment 7 by means of which it is ixed on one wall of the switch-casing, comprises an eX- tension 1a in which a switch-handle 15 is mounted, and carries all the elements of the mechanism. On a projection 14 a link 13 for a switch-rod 2 is pivotally mounted by means of a pivot-pin 12. The switch-rod 2, which has the form of a double bar as shown in Fig. 5, carries the contacts as usual. On a stud 11 fixed in the lock-plate a driving lever 3 formed by a plate is oscillatably mounted, the pointed end of which projects through between the two bars of the switch-rod 2, the handle 15 serving to operate said driving lever. A toggle-lever 4a, 4b connects the link 13 with the driving lever 3. An oscillatable lever 5 pivotally mounted on the stud 11 is connected by a link 6 to the middle joint of the toggle-lever 4a, 4b. Under the driving lever 3 a two-armed releasing lever 8, 9 is arranged pivotally mounted on a stud 16 xed on the lock-plate 1, the tri-angular arm 8 of this lever having at its free end a beak 8a projecting over the outer edge of the switch-rod 2. This beak is moved by any suitable overlead releasing means, such for instance as a bimetallic stripon the occur- Y rence of an overload. The arm 8 has a flange 18 bent towards the lockplate 1 and bearing against an adjusting screw 19 forming its abutment. A spring 10 the one endv of which is attached to a stud 20 of the lock-plate 1 the other end being attached to a hook 21 extending from the switch-rod 2, tends to pull the switch-rodv so that the contacts of the same move away from the counter contacts. An extension 29 of the lock-plate 1 projects between the two bars of the switch-bolt 2 to further guide the same. The arm 9 of the releasing lever 8 is connected to the corresponding end of the oscillatable lever 5 by a link 22, these two 4members 9, 22 forming a locking toggle. In a bridge 23 fixed near the si de-edge of the extension 1a of the lockplate (Fig. 6) a pivot-bolt 24 is mounted over f which grips the fork-shaped end 15a of the handle 15. The ends of the arms of the forkshaped end 15a are connected the one With the other by a bolt 25 on which a roller` 26 is rotatably mounted, each of said arms carrying a protecting disc 27. The roller 26 on bolt 25 is guided in an arc-shaped slot 28 concentric to the pivot-pin 24 and it traverses an oblique slot in the end of the driving lever 3.

When the handle 15, 15a has been turned by hand so that it drops under the action of gravity into the position shown in Fig. 3, the roller 26 on bolt 25 bears against the upper end of the arc-shaped slot 28. The corresponding arm of the driving lever 3 has been lifted, the switch-rod 2 has been lowered and the contacts are interrupted. In this position the toggle 4a. 47), which connects the link -13with the driving lever 3, is in stretched or approximately stretched position. The toggle-lever formed by the arm 9 and link 22 is also stretched and the bent flange 18 of the arm 8 bears against the adjusting screw19. The driving lever 3 is, so to say, clamped between the two pairs of toggle-levers 9, 22 and 4a, 4Z) which are in to it because it is retained bythe abutment 19. In consequence thereof the toggle 4a, 4b must remain in substantiallyr stretched position and the link 18 must move with the oscillating driving lever so that it will pull up the switch-rod 2 in putting under tension the spiral-spring 10 attached to said switch-rod (Fig. 1) The complete mechanism remains in this position as soon as the bolt 25 with its roller 26 has arrived at the end of the inclined slot 30 of the driving lever. switch is switched in (Figi) When owing to overloads such as a short circuit, `the tripping relay consisting for instance of bimetal-strips,-not shown-moves the releasing means or lever 8 is oscillated so that the toggle-lever 9, 22 collapses instantaneously and the locking effected by the same is suppressed; the oscillatable lever 5 loses its support at the lower end and the switch-rod 2, pulled by the action of spring 10, will make the toggle 4a, 4b collapse through the intermediary of the link 13, as

the elbow of this toggle-lever is relieved, 1. e. the switch is therefore released (Fig. 2) Y As however, owing to gravity, the handle 15 has been turned down, as shown in Fig. 3, it brings the lever-mechanism automatically into the stretched position so that it is merely necessary to lift the handle by hand for bringing the switch again into the operative position.

As all the elements of the chainof togglelevers are placed flatly the one on the other, the switch-lock itself is quite flat, and as some of the levers of this chain are of equal size, Itiht manufacturing is considerably simpli- The distance through which the thermic relay has to shift the armS can be regulated according to the prevailing conditions by the adjusting screw 9.

As will be seen by the specification the joints of the levers of the locking toggle remain at rest when the handle vis turned by hand in one and the other direction.

1. Actuating and locking device for switches of the trip-free-from-the-handle type comprising a switch-rod, a spring tending to move .the said switch-rod into open contact position, a handle, a toggle adapted to transmit the movement of said handle on Thev said switch-rod and to transmit a component of the force of said spring to a collapsible locking toggle, the joints of the links of' the said locking toggle being so selected that they remain at rest during the switch-in and the switch-off movement of said handle, the first mentioned toggle being connected to a rotatable plate provided with a slot, and a pin of the said handle engaging the said slot.

2. Actuating and locking device for switches ofV the trip-free-from-the-handle type comprising a switch-rod, a spring tending to move the said switch-rod into open contact position, a handle, a rotatable plate adapted to be driven by the said handle, a toggle adapted to transmit the movement of said rotatable plate to said switch-rod and to transmit a component of the force of said spring to a collapsible locking toggle, a link of the first mentioned toggle being jointed to said rotatable plate, a stationary abutment for normally maintaining the links oflsaid locking toggle in substantially coaxial position, releasing means for collapsing said locking toggle, the joints of the saidlinks being so selected that they remain at rest during the switch-in and theswitchl-off movement of said handle, a pin on the said handle, the said rotatable plate having a slot in which the pin engages, a link in the form of a twosided lever-mounted for pivotal movement about the same aXis as that of the rotatable plate, one end of the said last mentioned lever being linked to one end of the locking toggle, the middle joint of the first mentioned toggle being connected to the other end of the said lever through the intermediary of an additionallink.

3. A switch lock, comprising, in combination with the lock plate, a switch-rod, a spring pulling said switch-rod out of the contactposition, a driving lever for moving said switch rod in the contact-position in opposition to the said action of said spring, a link connecting the upper end of said switch-rod with a stationary point on said lock plate, a toggle connecting said link to said driving lever, a second toggle lever underneath said driving lever adapted to be operated by suitable releasing means, and means for connecting said second mentioned toggle to said first slot on the side of its pivotal connection with the lock plate being opposite its connection with the first mentioned toggle and said lock plate having an extension, a pivot pin inserted in said extension, the latter having an arc-shaped slot concentric to said pivot pin,

a handle pivotally mounted on said pivot pin and having a fork-shaped inner end, a transverse bolt connecting the free end of said fork-shaped part of said handle extending through said arc-shaped slot in the extension of the lock plate and through the oblique slot in said driving lever, the means for connecting said two toggles consisting of a rocking lever oscillatably mounted on the same pin as driving lever, a link connecting the one end of said locking lever with the middle pin of the first mentioned toggle, the other end of said rocking lever being connected to one end of the second mentioned toggle-lever.

4. A switch lock comprising in combination With the lock plate, a switch-rod, a spring pulling said switch-rod out of the contactposition, a driving lever for moving said switch-rod in the contact-position in opposition to the action of said spring, a link connecting the upper end of said switch-rod with a stationary point on said lock plate, a toggle connecting said link to said driving lever, a releasing device underneath said driving lever adapted to collapse a second toggle, said rst mentioned toggle being connected With the second mentioned toggle, links connecting the middle joint of the first mentioned toggle with one end of the second mentioned toggle, an abutment for the latter adapted to hold it in nearly stretched position, means for withdrawing said second mentioned toggle from said abutment to permit collapse of said two toggles, said switch-rod under the urge of said spring being free to move With said link to open contact-position independently of the position of said driving lever.

In testimony whereof I affix my signature.

ERNST BESAG. 

